New powerplant for the Sears Sportster!!!

[prettynifty4u]

Well gentleman after endless weeks of searching I finally ran across the right deal, and the new motor for the sears sportster is (drum roll please) a special series Kohler Command 22 hp with only 200 hrs (for some reason this spec # on this motor has alot larger stroke and bore than the standard 22hp, so this one actually falls around the 24hp range.) The greatest thing about it was that I found it locally on craigslist for only $400.00 and as you can see in the pictures it looks brand new. This guy took really goood care of it and I cant wait to get it going!!! Let me know how you all think this motor is going to do!!

[jpswift1]

First you get one of the best deals ever on the Sportster, and now you get a bulletproof Kohler 4 stroke for next to nothing to power it.....wow! I think you're going to have one of the best Sears Sportsters out there when you're done! That Kohler, behind the T-20 is one of the most durable and reliable drive train combinations for an AATV.

[prettynifty4u]

Engine Mount!

Thanks Jeff,
I hope it is going to be a tuff machine, I am also going to be able to get a little money back on the engine purchase because I am going to sell the electric dual pulley clutch off of it they sell for about $175 on ebay and this one is like new.

I was also wondering if anyone has had any problems with mounting these heavy four stroke engines on the original 2 stroke engine plate that has 4 vertical rubber shock mounts and one horiz. rubber shock mount??? Or do you have to go another route??

[Meinfield]

Sounds like you are off to a good start with the engine! Kohler would sometimes under rate their engines for their OEM customers, so it is possible that you have the 25hp block and internals with a smaller carburetor, and if it is an older engine it will have the chrome lined cylinders; if the oil is changed regularly and the engine is taken care of it will last a LONG time. If you post the bore and stroke I can help you figure out what you have. Anyhow, you got it for a good price!
As far as the motor mount is concerned, you need a flat surface to mount the case to at least as large as the bottom of the engine case and probably no less than 3/16" thick. These cases are aluminum and a certain amount of "flex" is normal, but a flat surface that is as large as the bottom of the case will help minimize this and probably extend the life of your engine, IMO. I had a machine shop cut 3/16" plate steel and punch holes in it for the motor mounts in my hustler. You can also purchase 1" polyurethane scrap from a gasket supply house and cut motor mounts with a hole saw.
Post some pictures, and good luck on the build!

[prettynifty4u]

Bore and Displacement

Meinfield,

I actually got the manual with the motor and here is what I found:

Standard 22 hp CH22
Bore 3.03 in / Displacement 38.1 in^3

Standard 25 hp CH25
Bore 3.27 in / Displacement 44 in^3

The 22hp I bought CH22 with Spec # 765
Bore 3.15 in / Displacement 41.1 in^3

It is bigger than the standard 22, Im thinking the reason why is this motor has the set up in the front of the shroud for a PTO shaft input, as for the mount I am going to get all new motor mounts from Mc Master Carr and beef up the original plate.

[Robio_8x8]

What was the original motor size for the sears?

I am sure that 22hp motor would make the Sportster boot

what was the original size motor ?

[prettynifty4u]

Orig. Motor

According to some reading Im pretty sure that it came with a 295 JLO, when I got the sportster it was motorless, I have no doubt that the frame, it is built really stout (and from what I hear the T-20) will handle the power.

[hdble]

Meinfield,

I actually got the manual with the motor and here is what I found:

Standard 22 hp CH22
Bore 3.03 in / Displacement 38.1 in^3

Standard 25 hp CH25
Bore 3.27 in / Displacement 44 in^3

The 22hp I bought CH22 with Spec # 765
Bore 3.15 in / Displacement 41.1 in^3

It is bigger than the standard 22, Im thinking the reason why is this motor has the set up in the front of the shroud for a PTO shaft input, as for the mount I am going to get all new motor mounts from Mc Master Carr and beef up the original plate.

Sounds like a hard combo to beat,you ought to have a very nice machine when you get it all done. Sounds bullet proof,Kohler, T-20, heavy frame well built, should last you a long time. alot of years of enjoyment there.
Another user of the great folks at McMaster-Carr, if they don't have it, your likely not to need it and they usually deliver in 24 hrs.
I buy anything I can from the guys, they are very good to me.

[jerseybigfoot]

Order the hardest rubber mounts for the Kohler. I originally installed my 20 HP Command with soft mounts and found too much flex and loss in converter performance and had to upgrade later.

[Meinfield]

I buy anything I can from the guys; they are very good to me.

Hdble,
I can spend hours on their website...kind of like a kid at Christmas time!

prettynifty4u,
Looks like you have one of the newer Ch22's, a fine engine. You can adjust the governor to spin 4000 rpm's with out any reliability issues. I have seen guys spin their stock engines a lot higher with good results, but you just never know if the rods will hold together. Kohler made fairly beefy rods in these engines, but they are cast, and if you are unlucky enough to get a poor casting they can break at higher rpm's. Also, a new exhaust and K&N air filter will really wake that engine up!
Good luck on the build.

[mad_max_500cc]

i would talk to the guys at receratives they have a realy stiff motor mount setup they use on their kohler engines i have the setup in my max and the darn thing dosent flex at all and still has enough rubber to keep it isolated the setup looks easy to adapt to just abought anything!

[prettynifty4u]

RI Motor mount

Does anyone have a pic of this motor mount they can post, possibly one that they are working on with the motor out, so I can see if it will work??

[jpswift1]

I don't have a picture but it looks like a 1" tall aluminum cylinder with some very hard rubber, or possibly a poly type plastic melted onto the top of it (this part helps absorb shock/vibration). There is very little give with this mount. I might be up at Recreatives after work today so I will snap a picture for you if I'm there.